GENERAL INFORMATION
The thyroarytenoid muscle is a critical component in the larynx and is responsible for controlling vocal cord tension. By adjusting the length and thickness of the vocal cords, it plays a significant role in voice modulation. Located within the larynx, this muscle contributes to both relaxing as well as shortening the vocal cords, which allows for variations in pitch, making it essential for speech as well as singing.
ORIGIN
The thyroarytenoid muscle originates from the inner surface of the thyroid cartilage, near the laryngeal prominence (commonly known as the Adam’s apple).
INSERTION POINT
It inserts into the anterolateral surface of the arytenoid cartilage, which is located in the posterior part of the larynx.
MAJOR ARTERIES
- Superior Thyroid Artery: A branch of the external carotid artery that provides the primary blood supply to the thyroarytenoid muscle.
- Inferior Laryngeal Artery: This artery supplements blood flow to the lower regions of the larynx, including the thyroarytenoid.
NEURAL INNERVATION
- Recurrent Laryngeal Nerve: A branch of the vagus nerve, this nerve is responsible for the motor control of the thyroarytenoid muscle, enabling fine adjustments to vocal cord tension.
TRIGGER POINT
Overuse of the thyroarytenoid muscle can result in soreness, hoarseness, and discomfort, particularly after extended periods of talking or singing. This discomfort can manifest as voice fatigue, which may feel like a strain in the lower throat area.
CONCENTRIC FUNCTION
During concentric contraction, the thyroarytenoid muscle shortens the vocal cords, decreasing tension and lowering the pitch of the voice. This action is crucial for producing deeper, richer sounds during vocalisation.
ECCENTRIC FUNCTION
When the thyroarytenoid muscle lengthens in eccentric contraction, it allows the vocal cords to relax gradually, enabling smoother transitions to higher-pitched sounds or pauses between speech.
ISOMETRIC FUNCTION
The thyroarytenoid muscle can maintain a stable contraction without changing length, holding the vocal cords in a fixed position to sustain a consistent pitch or sound during prolonged phonation.
RELATED MUSCLES – SCIENTIFIC NAMES
- Cricothyroid Muscle: Tenses the vocal cords, helping with a higher pitch.
- Posterior Cricoarytenoid Muscle: Abducts the vocal cords for breathing.
- Lateral Cricoarytenoid Muscle: Adducts the vocal cords to close the glottis.
- Vocalis Muscle: Works with the thyroarytenoid to fine-tune vocal cord tension for precise sound production.
ANTAGONIST
- Cricothyroid Muscle: Opposes the thyroarytenoid by increasing tension in the vocal cords, raising the pitch of the voice.
COMMON INJURIES
- Vocal Cord Strain: Often caused by overuse, resulting in hoarseness as well as difficulty controlling pitch.
- Laryngitis: Inflammation of the laryngeal muscles, including the thyroarytenoid, leading to temporary voice loss or a raspy voice.
- Vocal Cord Nodules: Small growths on the vocal cords caused by excessive use, leading to a breathy or strained voice.
- Thyroarytenoid Muscle Dysfunction: This occurs when the muscle fails to properly relax or contract, affecting voice control.
- Vocal Fatigue: Common in individuals who frequently use their voice for long periods, resulting in a strained, weak voice.
EXERCISES
- Lip Trills: Blow air through your lips while producing sound. This simple exercise helps activate the thyroarytenoid muscle by promoting relaxation and improving vocal endurance.
- Pitch Glides: Move smoothly from low to high pitches and back again. This exercise strengthens the thyroarytenoid, improving vocal range and control.
- Vocal Sirens: Slide through a wide range of pitches, mimicking a siren sound. This exercise helps engage and strengthen the muscles, improving flexibility and range.
- Sustained Vowel Sounds: Hold vowel sounds (like “O” or “A”) at different pitches for several seconds. This exercise strengthens the thyroarytenoid muscle, enhancing vocal stamina.
- Falsetto Practice: Sing in a falsetto voice to engage the thyroarytenoid muscle in higher pitches, helping it relax and stretch to its full potential.
STRETCHES
- Neck Tilts: Slowly tilt your head towards each shoulder, holding for 20-30 seconds. This stretch relieves tension in the surrounding neck muscles, indirectly benefiting the thyroarytenoid.
- Neck Rotation: Gently rotate your head in a circular motion to relax the muscles around the larynx. This stretch helps reduce tension that can impact vocal control.
- Jaw Stretches: Open and close the jaw while stretching it as wide as possible. This stretch relieves tightness around the throat as well as laryngeal muscles, helping to ease the strain on the thyroarytenoid.
- Tongue Stretch: Extend your tongue as far out as you can and hold for 10 seconds. This stretch helps loosen the muscles at the base of the tongue, reducing tension in the vocal cords.
- Shoulder Shrugs: Raise and lower your shoulders slowly to reduce upper body tension that can affect the neck as well as the larynx. This relaxation indirectly supports the thyroarytenoid muscle function.